Difference between String.valueOf & int + “”

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Internals of String s = String.valueOf(i);

How it works

• Calls a method in the String class.
• Internally converts the integer using optimized logic.

Implementation

public static String valueOf(int i) {
    return Integer.toString(i);
}

public static String toString(int i) {
    if (i == Integer.MIN_VALUE)
        return "-2147483648";

    int size = stringSize(i);
    char[] buf = new char[size];
    getChars(i, size, buf);
    return new String(buf);
}

public static String getChars(int i, int size char[] buf){
  while (i >= 10) {
    int q = i / 10;
    int r = i % 10;
    buf[--pos] = (char) ('0' + r);
    i = q;
  }
  buf[--pos] = (char) ('0' + i);
  return new String(buf);
}

Why It’s Fast

String.valueOf(i) is efficient because:

• ✅ No StringBuilder
• ✅ No temporary strings
• ✅ Uses pre-sized char[]
• ✅ Minimal allocations

(2) Internals of int(i) + “”

new StringBuilder().append(i).append(“”).toString();

That means:

• Create StringBuilder
• Convert int inside append
• Append empty string
• Convert back to String

I used ChatGpt for my research. Hope this helps you in string conversion.

May Allah bless you, take care.